JSONPlaceholder is a free online REST service that you can use whenever you need some fake data. It’s great for tutorials, faking a server, sharing code examples. Try it, and send some HTTP-verb requests like GET, POST, PUT, and DELETE.

The Open Trivia Database provides a completely free JSON API for use in programming projects. Use of this API does not require an API Key, just generate the URL below and use it in your own application to retrieve trivia questions.

Registration: None

Wrapping up, you don’t have to create your own web service. There are free public APIs that you can use for you to get started with Xamarin Forms and REST APIs.